Optical ring resonator-based microfluidic sensor

Abstract

Disclosed is a structure (e.g., a lab-on-chip structure) including a substrate, an insulator layer on the substrate, and at least one optical ring resonator. Each ring resonator includes cladding material on the insulator layer and, embedded within the cladding material, a first waveguide core with an input and an output, and second waveguide core(s) (e.g., ring waveguide core(s)) positioned laterally adjacent to the first waveguide core. A reservoir is below the ring resonator within the insulator layer and substrate such that surfaces of the waveguide cores are exposed within the reservoir. During a sensing operation, the waveguide core surfaces contact with fluid within the reservoir and a light signal at the output of the first waveguide core is monitored (e.g., by a sensing circuit, which in some embodiments is also coupled to a reference optical ring resonator) and used, for example, for spectrum-based target identification and, optionally, characterization.